Pipeline leak-testing method

ABSTRACT

A method for leak-testing a pipeline system, of the type having a test tee fitting in a standpipe, includes attachment of a leak-testing device to an opening of the test tee. A water hose is coupled to a threaded bushing of the leak-testing device for passing water through a one-way valve into the interconnected pipeline system. After leak testing is completed, a sealing cap is secured over the threaded bushing, and the device is left permanently in place after the test is completed.

CROSS-REFERENCE TO RELATED APPLICATIONS

This patent application is a divisional patent application of U.S.patent application Ser. No. 10/670,048, filed Sep. 23, 2003 now U.S.Pat. No. 6,912,890, which in turn, is a continuation in part of U.S.patent application Ser. No. 10/208,982, filed Jul. 31, 2002 nowabandoned, and the benefit of such earlier filing dates are herebyclaimed by Applicant under 35 U.S.C. §120.

FIELD OF INVENTION

This invention relates to the testing of pipeline systems for leaks, andmore particularly, to a permanent leak-testing device that permits theflow of fluid into a pipeline system through the device, andautomatically seals itself via a one-way valve to prevent any leakageout of the pipeline system.

BACKGROUND

In general, the integrity of fluid-based, interconnected pipelinesystems must be tested for leaks. This type of testing is applicable tooil pipeline systems, commercial wastewater systems, and residentialplumbing systems, among others. During the construction of a building,for example, a plurality of drainage pipes are interconnected so thatsewage or waste water may flow from multiple sources down a singledrainage system. The pipeline system is inspected for leaks and mustpass government inspection before occupancy is permitted.

Pipes for tubs, showers, sinks, and toilets, are interconnected and makea final connection to a stand-pipe or vent stack that extends severalfeet above ground level. The stand-pipe is coupled to the pipelinesystem to prevent the formation of a vacuum generated by fluid in thepipes. A test tee is typically installed at the junction between thestand-pipe and the remainder of the pipeline system to create a site fortesting the integrity of the system. A conventional test tee includes aT or Y fitting in an elongate tubular member, which is permanentlyinstalled in the stand-pipe or the stack of sewage sections. The testtee includes an accessible opening, which is conventionally used toisolate a portion of a building's plumbing system with an air-filledballoon or other stopper device or to attach a device for filling thestand-pipe with water. Multiple test tees can be installed throughoutlarge or multi-level pipeline projects to test specific areas.

To test the pipeline system, the stand-pipe is filled with water throughthe test tee and the pressurized pipeline system is inspected todetermine if any leaks exist. Once the inspection of the system iscompleted, the water is released from the stand-pipe through the testtee and usually gushes onto the ground or floor.

Various prior art devices have been designed which are removablyattachable to the test tee to cap its opening so that the pipelinesystem stays pressurized until inspected. One such device is a bushingand hose bib arrangement (“bushing/bib”) made of off-the-shelf,standardized parts in which a plastic bushing is connected to a brasshose bib (spigot). The bushing/bib is screwed into the opening of thetest tee. A plumber fills the pipeline system with water from a gardenhose and seals the stand-pipe temporarily by closing the spigot. Afterthe test is complete, the bushing/bib must be removed and replaced witha permanent cap.

One problem with the bushing/bib and other prior art devices is the costof using these devices. Having a brass component, the bushing/bib isrelatively expensive, even though; it is reusable. However, thebushing/bib devices are often stolen—after the inspection—before theplumber can return to replace the bushing/bib with an inexpensive,permanent threaded plastic cap to cover the test aperture.

Another problem with the prior art devices is the potential water damagethat can occur when the devices are removed after testing. The prior artdevices are not designed to be permanent fixtures. Such a device cannotbecome a permanent fixture of the system and must be removed. When theprior art device is removed—either by a plumber or by a thief—aconsiderable volume of water flows outward from the opening of the testtee, which sometimes causes flooding and damage to the floor of thebuilding and surrounding areas.

On the other hand, since such prior art testing devices are not intendedto be permanent fixtures, significant problems can also arise if theyare inadvertently left in the test fixture, and construction iscompleted. For example, U.S. Pat. No. 5,076,095 to Erhardt discloses adevice having a paddle-shaped sealing member coaxially coupled to afreely rotatable threaded cap member which removably engages the teefitting in a plumbing system vent stack. The paddle selectively extendsacross and seals the pipeline. The Erhardt device includes a one-waycheck valve to introduce pressurized fluid into the plumbing systemabove the aforementioned paddle inside the tee fitting. Thepaddle-shaped sealing member of the Erhardt device extends across, andeither entirely blocks or partially restricts, the flow path in the tee.Many city codes prohibit any such blockage or restriction in theplumbing line; thus, if one forgets to remove the Erhardt device beforecovering over the plumbing line with drywall, the resulting structure isin violation of the city code. Additionally, if the Erhardt device wereinadvertently left within the test tee, the paddle-shaped sealing membercould later rotate to its closed position (i.e., upon a sudden rush ofwater) and seal off the pipe, leading to either undesired vacuums withinthe plumbing system, or possibly flooding. Furthermore, were theaforementioned Erhardt device inadvertently left in the test tee, andthen covered over by drywall, water could eventually leak out from thetest tee behind walls of the structure, causing the formation of mold.

Therefore, it is an object of this invention to provide a leak-testingdevice that significantly contributes to the ease and low cost involvedin the inspection of a pipeline system for leaks. It is a further objectof the invention that the leak-testing device may serve as a permanentattachment to the test tee so that removal is not required, therebyavoiding the expenses of having a plumber return to replace it or ofhaving it stolen. It is a further object of this invention to have aleak-testing device made of inexpensive materials.

It is a further object of the invention that the leak-testing device mayserve as a permanent attachment to the test tee so that removal is notrequired, thereby avoiding flooding of the foundation of the building orthe area beneath the fluid-based pipeline system.

Another object of the present invention is to provide a leak-testingdevice that may be attached to the test tee of a pipeline system in sucha way that fluid may be channeled through the testing device into thetest tee.

It is a further object of the invention that the leak-testing device isleakproof so that no fluid escapes out of the testing device.

Further objects and advantages of the present invention will becomeapparent from the study of the following portions of this specification,the claims and the attached drawings.

SUMMARY OF THE INVENTION

The present invention is a device for leak testing a pipeline systemwhich can be left in place after the test is completed. The pipelinesystem includes a standpipe having a tee fitting; the tee fitting hasfirst and second opposing openings axially aligned with each other, aswell as a third opening having internal threads. A generally circularbase plate, or “threaded collar”, has a threaded outer periphery forthreadedly engaging the internal threads of the third opening of the teefitting. The generally circular base plate has a fluid passage, orchannel, extending centrally therethrough. A wrench collar is attachedto the generally circular base plate and is preferably integraltherewith; the wrench collar is adapted to be engaged by a wrench fortightening the generally circular base plate within the third opening ofthe tee fitting.

The leak testing device also includes a threaded bushing having a fluidpassage, or channel, extending centrally therethrough. If desired, thethreaded bushing may be connected to the generally circular base platevia the wrench collar, and in that instance, the wrench collar alsoincludes a fluid passage, or channel, aligned with those of the baseplate and threaded bushing. Preferably, the threaded bushing, wrenchcollar, and generally circular base plate are all integral with eachother. The fluid passage of the threaded bushing is axially alignedwith, and in fluid communication with, the fluid passage of thegenerally circular base plate to form a fluid channel therewith. Thethreaded bushing is adapted to engage an end of a water supply hose,having mating threads, to fill the standpipe with water through theaforementioned fluid channel. The threaded bushing may beinternally-threaded to receive the male end of a water hose;alternatively, the threaded bushing may be externally-threaded toreceive the female end of a water supply hose. A one-way valve isdisposed within the aforementioned fluid channel for admitting waterthrough the fluid channel into the standpipe, while preventing waterfrom escaping through the fluid channel out of the standpipe. Theleak-testing device is attachable to the third opening of the teefitting of the standpipe without extending into, and without obstructingfluid flow within, the tubular section of the tee fitting.

Preferably, the leak testing device includes a cap to cover and seal thethreaded bushing after leak-testing is completed. The sealing cappreferably has threads which mate with the threads of the threadedbushing. Ideally, the threaded bushing and sealing cap are made fromplastic material ordinarily used to form PVC or ABS plastic plumbingpipe, and solvent bonding cement is applied to the mating threads beforethe cap is applied to form a leak-proof seal.

The one-way valve preferably includes a valve seat having at least oneaperture therein, and a deformable valve disposed proximate the valveseat. In the preferred embodiment, the valve is an umbrella valve. Thevalve seat and deformable valve element are located within the generallycircular base plate, within the wrench collar, and/or within thethreaded bushing; thus, the valve is essentially internal to the leaktesting device, and does not extend into, or obstruct flow within, thetubular section of the tee fitting. The valve seat may be positionedanywhere within the central fluid channel of the leak testing device; ifdesired, the valve seat may be disposed between the base plate and thewrench collar, or between the wrench collar and the threaded bushing.

In the preferred embodiment, a bushing—designed to receive a matingcap—is attached to a wrench collar and a threaded collar, all of whichshare a common axis. A pressure-activated one-way valve rests against avalve seat disposed along the common axis. The one-way valve does notextend into the tubular section of the tee fitting, and does not blockthe flow path in the tubular section of the tee fitting; rather, theone-way valve is preferably disposed within the leak testing deviceitself, at a point located somewhere between the threaded collar and thethreaded bushing of the leak testing device.

Furthermore, the leak testing device does not include any componentswhich protrude inside the tubular section of the tee fitting. Thus, theflow path inside the tubular section of the tee fitting remainsunobstructed by the leak testing device, even though the leak testingdevice is left permanently within the tee fitting. Fluid passes from thehose through the one-way valve into the interconnected pipeline system.When the operator shuts off the fluid flow, the pressure from the fluidthat has been pumped into the pipeline system causes the one-way valvein the device to seat itself across the valve seat, thereby preventingfluid from leaking out the leak-testing device. After the operatorcompletes the testing for leaks in the pipeline system, the hose isremoved and a cap may be attached to the bushing. The leak-testingdevice does not need to be removed—it becomes a permanent fixture.

Another aspect of the present invention relates to a new and improvedmethod of leak testing such a pipeline system. A leak testing device isprovided for being engaged with the third opening of the tee fitting.Such leak testing device may include a generally circular base plate, or“threaded collar”, having a threaded outer periphery for mating with theinternal threads of the third opening of the tee fitting; a fluidpassage, or channel, extends centrally through the generally circularbase plate. This leak testing device also preferably includes a wrenchcollar provided on the generally circular base plate, whereby a wrenchis engaged with the wrench collar for tightening the generally circularbase plate within the third opening of the tee fitting. A threadedbushing is provided, the threaded bushing having a fluid passageextending centrally therethrough; the fluid passage of the threadedbushing is axially aligned with, and in fluid communication with, thefluid passage of the generally circular base plate to collectively forma fluid channel. A one-way valve is formed within the fluid channel foradmitting water through the fluid channel into the standpipe, whilepreventing water from escaping through the fluid channel out of thestandpipe.

The end of a water hose is attached to the threaded bushing, and thepipeline system is substantially filled with water; the water hose maythen be detached. The pipeline system is then checked for leaks, afterwhich the aforementioned leak testing device (e.g., the generallycircular base plate, wrench collar, threaded bushing, and one-way valvecomponents) are permanently left in place within the third opening ofthe tee fitting. Preferably, a sealing cap is engaged over the threadedbushing after leak testing is completed to prevent any later waterleaks. Ideally, the threaded bushing and sealing cap are made ofplastic, and plastic cement (e.g., a solvent bonding cement, such as PVCcement, or other sealing material) is applied to the threaded bushing,to the sealing cap, or to both such components, before engaging thesealing cap over the threaded bushing to lock the cap in place. Thisformation of this water-tight seal between the cap and the threadedbushing, after completion of leak testing, prevents subsequent waterleakage, which might otherwise result in mold growth behind a wallerected after testing is completed.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a perspective view of the leak-testing device according to apreferred embodiment of the invention, along with a typical tee fittinginto which the leak-testing device may be attached.

FIG. 2 is a perspective view of the leak-testing device shown in FIG. 1,as well as a mating sealing cap.

FIG. 3 is a cross-sectional view of the leak-testing device of FIGS. 1and 2 taken along line 3-3 of FIG. 2, and also showing a water supplyhose with a female, internally-threaded coupling end, which may beattached to the leak-testing device.

FIG. 4 is a top view of the leak-testing device shown in FIGS. 1-3.

FIG. 5 is a side view of the one-way umbrella valve that seats againstthe valve seat shown in FIG. 4.

FIG. 6 is a view similar to that of FIG. 3, but wherein the water supplyhose has an externally-threaded male end to mate with a threaded bushinghaving internal threads, in accordance with an alternate embodiment ofthe invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

A leak-testing device in accordance with a preferred embodiment of thepresent invention, designated generally by reference numeral 10, isillustrated with reference to FIGS. 1-5. In FIG. 1, leak-testing device10 is shown along with a generic test tee fitting 11. Test tee fitting11 is shown installed as part of a standpipe 9. Tee fitting 11 includesan elongated tubular section 22 extending between first and secondopposing openings 7 and 8 that are axially aligned with each other, andwhich are co-axial with the normal flow path through the standpipe 9.Tee fitting 11 includes a third opening 15 communicating with tubularsection 22 of tee fitting 11. Typically, third opening 15 has internalthreads formed thereon. Leak testing device 10 is installed into thirdopening 15 of tee fitting 11.

As shown in FIG. 1, leak-testing device 10 includes a generally circularbase plate 12, sometimes referred to herein as a “threaded collar”. Baseplate 12 has a threaded outer periphery for threadedly engaging theinternal threads of third opening 15 of tee fitting 11. As shown best inFIG. 3, base plate 12 is essentially hollow and has a fluid passageextending centrally therethrough;. Wrench collar 13 is attached to theupper surface of base plate 12, and is preferably formed to be integraltherewith. The purpose of wrench collar 13 is to permit a wrench orother tool to tighten base plate (threaded collar) 12 within thirdopening 15 of test tee 11. Wrench collar 13 is preferably square inshape, but it could also be hexagonal or some other non-circular shape.As shown best in FIG. 3, the interior of wrench collar 13 is also hollowand provides a fluid passage coaxial with, and continuous with, thefluid passage of base plate 12. Note that while wrench collar 13 isillustrated as extending across the central region of the upper surfaceof base plate 12, wrench collar 13 may also be devised with tabs thatprotrude from base plate 12 for being gripped by a wrench or other tool.

A bushing 14 is attached to, and extends from, the upper surface ofwrench collar 13; preferably, bushing 14 is formed to be integral withwrench collar 13 and base plate 12. In the embodiment of the inventiondepicted in FIGS. 1-5, bushing 14 is an externally-threaded bushingadapted to engage a female end 31 of a water supply hose (see FIG. 3) tofill standpipe 9 with water. Alternatively, as shown in FIG. 6, bushing14 may instead be internally threaded to receive the male threaded end35 of a water supply hose 36. Bushing 14 has a fluid passage 16extending centrally therethrough; fluid passage 16 is axially alignedwith, and in fluid communication with, the corresponding fluid passagesof wrench collar 13 and base plate 12. Thus, bushing 14, wrench collar13, and threaded collar 12 are interconnected along a common axis tocollectively form a fluid channel.

Leak testing device 10 includes a one-way valve disposed within theaforementioned fluid channel for admitting water into the standpipe 9for testing purposes, while preventing water from escaping through suchfluid channel out of standpipe 9. To this end, a valve seat 30 (havingat least one aperture formed therein) is disposed across the fluidchannel (see FIGS. 3 and 4), and a deformable valve member 20, having avalve head 33 (see FIGS. 3 and 5), is disposed proximate valve seat 30for selectively seating against valve seat 30. In the preferredembodiment, valve seat 30 is formed between bushing 14 and wrench collar13, at the point where bushing 14 merges with wrench collar 13, as shownin FIG. 3. However, valve seat 30 could instead be located betweenwrench collar 13 and threaded collar 12. In general, valve seat 30 couldbe located anywhere along the central fluid channel collectively formedby base plate 12, wrench collar 13 and bushing 14. In any case, valvemember 20 does not extend into tubular section 22 of tee fitting 11, anddoes not block the standpipe flow path through tubular section 22 of teefitting 11. Furthermore, leak testing device 10 does not include anycomponents which protrude into the tubular section 22 of tee fitting 11,as might block the flow path therethrough. While it is not necessary toposition valve member 20, or valve seat 30, below the bottom 24 of baseplate 12, it should be noted that there is typically some open spacebetween bottom 24 of base plate 12 and the flow path of tubular section22 of tee fitting 11 after leak test device 10 is installed withinopening 15 of tee fitting 11. Accordingly, valve seat 30 and/or valvemember 20 could be disposed proximate to, but slightly below, bottom 24of base plate 12, if desired, without causing such components to extendwithin tubular section 22 of tee fitting 11, and hence, withoutobstructing the flow path in tubular section 22.

As illustrated in FIGS. 3 and 5, valve member 20 is preferably anumbrella valve. The manner in which this one-way valve functions andoperates in use is described in more detail below. It should be apparentthat other one-way valves—whether bought off the shelf or customdesigned—may also be used.

The leak-testing device described herein is intended primarily fortesting the plumbing system of a building for water leaks, although thedevice could be used on other types of pipeline systems having othertypes of fluids. In the embodiment shown in FIGS. 1-3, bushing 14 isexternally threaded to accommodate the female end 31 of a garden hose,or a common washing machine style water supply hose. As shown in FIG. 6,bushing 14 may instead be internally threaded to accommodate anexternally threaded male end 35 of a water hose 36, as shown in FIG. 6.However, bushing 14 may also consist of any alternative fashion forcoupling with a fluid source, such as a snap mechanism with afluid-tight seal.

When water under pressure is introduced into the central fluid channelof leak test device 10 through bushing 14, one-way valve 20 is forcedopen by the pressure of the water as it gushes through valve seat 30.The water pushes valve head 33 of one-way valve 20 toward the bottom 24of threaded collar 12. When the flow of water stops, the pressure fromthe water that has entered the pipeline system automatically closesone-way valve 20 by forcing valve head 33 against valve seat 30, therebysealing leak test device 10 so that the pipeline system may be testedfor leaks.

In the preferred embodiment, a sealing cap 21 screws onto threadedbushing 14 after the testing of the pipeline system is completed, asshown in FIG. 2. However, cap 21 may be attached by a differentmechanism, such as a cotter pin or a snap mechanism. In the preferredembodiment, solvent bonding cement, such as PVC cement, is applied tothe internal threads of cap 21, and to the external threads of bushing14, before cap 21 is threaded over bushing 14 in order to lock cap 21 inplace, and to thereby form a durable, water-tight seal between cap 21and bushing 14 for preventing water leakage after testing is completed.Thereafter, drywall may be installed to cover up standpipe 9, teefitting 11, and leak-testing device 10. Forming such water tight seal isimportant, since water leakage might otherwise foster mold growth behindthe plastered wall.

FIG. 4 shows a top view of leak-testing device 10. This view bettershows the structure of valve seat 30. In the preferred embodiment, valveseat 30 has eight triangular-shaped peripheral openings 41 spaced abouta center opening used to retain valve member 20, but the number andshape of such peripheral openings can vary.

FIG. 5 shows a side view of one-way valve member 20 in the form of anumbrella valve. However, any type of one-way valve may be utilized.One-way valve 20 preferably includes a raised flange 50, which holds thevalve in place within the center opening of valve seat 30. Raised flange50 prevents valve member 20 from disengaging from valve seat 30 andbeing lost into the pipeline system being tested.

The leak-testing device 10 is preferably made of molded plastic such asABS or PVC, but may be made of any corrosion-resistant material. Forease of manufacture and to guard against leaks, bushing 14, wrenchcollar 13 and threaded collar 12 are preferably formed to be integralwith each other.

Apart from providing a new and improved leak testing device, it will beappreciated that the applicant has also disclosed an improved method forleak-testing a pipeline system. In practicing such method, the userattaches leak testing device 10 to third opening 15 of tee fitting 11,as by threading base plate 12 into opening 15. The user then attachesfemale end 31 of the water supply hose to threaded bushing 14 of leaktesting device 10, and turns the water supply on to supply water throughthe one-way valve into standpipe 9 to substantially fill the standpipe.The water supply is then turned off, and the water supply hose isdetached from threaded bushing 14. The pipeline system is then testedfor leaks. Assuming that no leaks are uncovered, the user permanentlyleaves leak testing device 10 in place within third opening 15 of teefitting 11 after leak testing is completed. Leak testing device 10 canbe manufactured relatively inexpensively, and leaving it in place doesnot add significantly to construction costs. Ideally, sealing cap 21 isthen engaged over threaded bushing 14, as by engaging the mating threadsthereof, to permanently seal threaded bushing 14. As mentioned above,this seal is preferably enhanced by applying plastic cement to suchmating threads before engaging the sealing cap over the threaded bushingto form a permanent seal therebetween.

While there has been illustrated and described what is at presentconsidered to be the preferred embodiment of the present invention, itwill be understood by those skilled in the art that various changes andmodifications may be made, and equivalents may be substituted forelements thereof, without departing from the true scope of theinvention. Therefore, it is intended that this invention not be limitedto the particular embodiment disclosed as the best mode contemplated forcarrying out the invention, but that the invention will include allembodiments falling with the scope of the appended claims.

1. A method for leak-testing a pipeline system, the pipeline systemincluding a standpipe, the standpipe including a tee fitting, the teefitting having a tubular section extending between first and secondopposing openings axially aligned with each other, the tee fittingincluding a third opening communicating with the tubular section of thetee fitting and having internal threads, said method comprising thesteps of: a) providing a generally circular base plate having a threadedouter periphery for mating with the internal threads of the thirdopening of the tee fitting, the generally circular base plate having afluid passage extending centrally therethrough; b) providing a wrenchcollar on the generally circular base plate; c) disposing the generallycircular base plate within the third opening of the tee fitting; d)engaging a wrench with the wrench collar for tightening the generallycircular base plate within the third opening of the tee fitting; e)providing a threaded bushing having a fluid passage extending centrallytherethrough, the fluid passage of said threaded bushing being axiallyaligned with, and in fluid communication with, the fluid passage of thegenerally circular base plate, the fluid passage of said threadedbushing and the fluid passage of said generally circular base platecollectively forming a fluid channel; f) forming a one-way valve withinthe fluid channel for admitting water through the fluid channel into thestandpipe, while preventing water from escaping through the fluidchannel out of the standpipe; g) attaching the end of a water hose tothe threaded bushing and substantially filling the pipeline system withwater; h) checking the pipeline system for leaks; and i) permanentlyleaving the generally circular base plate, wrench collar, threadedbushing and one-way valve in place within the third opening of the teefitting after leak testing is completed.
 2. The method according toclaim 1 including the further step of engaging a sealing cap over thethreaded bushing after leak testing is completed.
 3. The methodaccording to claim 2 wherein the threaded bushing and sealing cap aremade of plastic, and including the further step of applying plasticcement to at least one of the threaded bushing and sealing cap beforeengaging the sealing cap over the threaded bushing.
 4. A method forleak-testing a pipeline system, the pipeline system including astandpipe, the standpipe including a tee fitting, the tee fitting havinga tubular section extending between first and second opposing openingsaxially aligned with each other, the tee fitting including a thirdopening communicating with the tubular section of the tee fitting andhaving internal threads, said method comprising the steps of: a)attaching a leak testing device to the third opening of the tee fitting,the leak testing device including a threaded bushing for receiving theend of a water supply hose, and including a one-way valve for admittingwater through the threaded bushing into the standpipe, while preventingwater from escaping through the threaded bushing out of the standpipe;b) attaching an end of a water supply hose to the threaded bushing ofthe leak testing device; c) supplying water to the threaded bushing andinto the standpipe through the leak testing device to substantially fillthe standpipe; d) testing the pipeline system for leaks; e) detachingthe water supply hose from the threaded bushing of the leak testingdevice; and f) permanently leaving the leak testing device in placewithin the third opening of the tee fitting after leak testing iscompleted.
 5. The method according to claim 4 including the further stepof engaging a sealing cap over the threaded bushing after leak testingis completed to permanently seal the threaded bushing.
 6. The methodaccording to claim 5 wherein the sealing cap and threaded bushing havemating threads.
 7. The method according to claim 5 wherein the threadedbushing and sealing cap are made of plastic, and including the furtherstep of applying plastic cement to at least one of the threaded bushingand sealing cap before engaging the sealing cap over the threadedbushing to form a permanent seal therebetween.